Hmm - Well this is just not wanting to play nicely at all....
Ive added another 2 links (Now 4 total), all equal cost - Egress load (From ASR920->ME3600) went from Gi0/0/22 doing 950M/sec, Gi0/0/23 doing 5-10Mb/sec, to Gi0/0/20 now taking all the load... So, we have gi0/0/20,21,22,23 connected to the "corresponding" ports on the ME3600 (gi0/20,21,22,23) Now gi0/0/20 is doing 970Mb/s a sec.....Ive tried every combination of load-sharing in global conf, and they initially make a bit of a difference (i.e. the other ports will do 5-10Mb/sec each), but then revert back to Gi0/0/20 being maxed out. #show int gigabitEthernet 0/0/20 | inc 30 sec 30 second input rate 90190000 bits/sec, 14882 packets/sec 30 second output rate 969898000 bits/sec, 144872 packets/sec #show int gigabitEthernet 0/0/21 | inc 30 sec 30 second input rate 74069000 bits/sec, 13780 packets/sec 30 second output rate 1778000 bits/sec, 312 packets/sec #show int gigabitEthernet 0/0/22 | inc 30 sec 30 second input rate 96760000 bits/sec, 15992 packets/sec 30 second output rate 3067000 bits/sec, 444 packets/sec #show int gigabitEthernet 0/0/23 | inc 30 sec 30 second input rate 103174000 bits/sec, 16690 packets/sec 30 second output rate 395000 bits/sec, 101 packets/sec Help? 😊 ________________________________ From: CBL <[email protected]> Sent: Thursday, 31 August 2017 1:13 PM To: CiscoNSP List Cc: James Bensley; [email protected] Subject: Re: [c-nsp] OSPF equal cost load balancing What if you were to setup four BDIs running OSPF/MPLS across these two physical interfaces. Two BDIs per physical interface. Would that make ECMP work correctly using an ASR920? We're going to be in the same boat soon too.. ASR920's on both sides with OSPF across two physical paths and worried about load sharing. Most of our traffic is MPLS xconnects traversing these links (licensed backhauls). On Wed, Aug 30, 2017 at 6:35 PM, CiscoNSP List <[email protected]<mailto:[email protected]>> wrote: AAh - Thank you James! So the ASR920 will not ECMP over 2 links, it requires 4...that would explain the difference between egress/ingress (and why the 920 is not working particularly well!) Yes, this is ECMP, not LAG - So changing the load sharing algorithm can only be done globally (As I tried to do it under the individual interfaces, and was only presented with per dst as an option) (config-if)#ip load-sharing ? per-destination Deterministic distribution So, changing globally will potentially cause a service disruption? (May need to do this in maintenance window) - Do you suggest "include-ports" as a possible candidate? #ip cef load-sharing algorithm ? include-ports Algorithm that includes layer 4 ports original Original algorithm tunnel Algorithm for use in tunnel only environments universal Algorithm for use in most environments And yes, we are running MPLS over these links (But not a LAG as mentioned) - So does your comment re MPLS hasting still apply to our setup, or only to a LAG? Thanks again for your response - Extremely helpful! ________________________________ From: cisco-nsp <[email protected]<mailto:[email protected]>> on behalf of James Bensley <[email protected]<mailto:[email protected]>> Sent: Thursday, 31 August 2017 6:43 AM To: [email protected]<mailto:[email protected]> Subject: Re: [c-nsp] OSPF equal cost load balancing I think two layer ECMP links are being used here, both of which are in the IGP. Are you running MPLS over these links too? The ME3600 is able to ECMP over any number of links as far as I know (up to the max, which is 8 or 16) however I think the ASR920 will only ECMP over 4 or 8 links (so not 2 as in your case). This could be the problem here. Could you also try to change the CEF load balancing algorithm (assuming this is ECMP and not LAG, this won't affect a LAG): ASR920(config)#ip cef load-sharing algorithm ? include-ports Algorithm that includes layer 4 ports original Original algorithm tunnel Algorithm for use in tunnel only environments universal Algorithm for use in most environments If it is a LAG then on the ASR920 try to adjust these options: ASR920(config)#port-channel load-balance-hash-algo ? dst-ip Destination IP dst-mac Destination MAC src-dst-ip Source XOR Destination IP Addr src-dst-mac Source XOR Destination MAC src-dst-mixed-ip-port Source XOR Destination Port, IP addr src-ip Source IP src-mac Source MAC If you're running MPLS over the LAG the ASR920 can hash MPLS over the LAG and the ASR920 should hash over 2 links just fine. Cheers, James. _______________________________________________ cisco-nsp mailing list [email protected]<mailto:[email protected]> https://puck.nether.net/mailman/listinfo/cisco-nsp cisco-nsp Info Page - puck.nether.net<http://puck.nether.net><https://puck.nether.net/mailman/listinfo/cisco-nsp> puck.nether.net<http://puck.nether.net> To see the collection of prior postings to the list, visit the cisco-nsp Archives. Using cisco-nsp: To post a message to all the list members, send ... archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected]<mailto:[email protected]> https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
